Serving tray



FIG. 1 is a top plan view of a serving tray, showing my new design;

FIG. 2 is a side elevation view of the serving tray looking from the left;

FIG. 3 is a side elevation view of the serving tray looking from the right;

FIG. 4 is a front elevation view of the serving tray;

FIG. 5 is a bottom plan view of the serving tray. 

The ornamental design for a serving tray, substantially as shown. 